Process and device for producing a laminated material for slide elements

ABSTRACT

A process for producing a laminated material for slide elements including at least one backing layer and at least one functional layer of a material frozen in the amorphous state and the backing layer.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national phase of PCT/DE 90/00365 filed May 17,1990 and based upon German National Application P3938234.6 filed Nov.17, 1989.

FIELD OF THE INVENTION

The invention relates to a process for the manufacture of a laminatedmaterial for slide elements with a sliding layer consisting of at leastone alloy in the form of a metallurgical two-component ormulti-component system with a miscibility gap (monotectic) which isapplied to a substrate. The invention also relates to a device forcarrying out the process.

BACKGROUND OF THE INVENTION

Alloys in the form of metallurgical two-component or multi-componentsystems with a miscibility gap (monotectic), also called dispersionalloys, generally consist of metallic components of very differentspecific weight. The heavy components, such as Pb in AlPb dispersionalloys have a strong tendency to segregate, for instance during thesolidification of the alloy. Initially more mixed crystals of adifferent concentration are separated than during the later stage ofcooling, so that the mixed crystals from the melt are not homogeneous.The manufacture of AlPb materials for use in slide bearings underterrestrial conditions using casting techniques is therefore madeimpossible for instance by the miscibility gap existing in the AlPbsystem. The fine distribution of lead in an Al-matrix required for usein a slide bearing material is not reached.

In connection with the production of functional layers of suchdispersion alloys, DE-OS 31 37 745 for instance discloses themanufacture of metal powders by atomization of a melt and its sinteringonto a substrate. However, this method provides a very nonhomogeneousstructure, so that the results fluctuate considerably when tested in amachine for slide-bearing testing. In addition, it had been found thatas a result of the inner notch effect, the pores which are still presentin the sintered layer cause cracking when the slide element is subjectedto alternating loads

From DE-AS 15 08 856 a method is already known which requires the use ofcontinuous casting for aluminum alloys with a high content of lead.Thereby, a homogeneous one-phase melt of an aluminum-lead alloycontaining 20 to 50% lead is cast onto a metallic substrate to directlyproduce a composite bearing material. However, this method leads to adefective bond of the AlPb sliding layer (functional layer) with thesteel. Moreover, in spite of cooling with water, separation takes placeeven in the mold, which means that the temperature gradient between thetemperature of the homogeneous melt and the mold temperature is toosmall, so that the onset of the thermodynamic equilibrium can notprevented. The result is a sliding layer with a homogeneous, segregatedstructure; a two-layered tribologically non-usable sandwich results,which in addition has the disadvantage of poor bonding with thesubstrate.

Also, from DE-PS 21 30 421 and DE-OS 22 41 628 methods for theproduction of composite metal strips are known, wherein molten aluminumexits through an opening in the bottom of a melting crucible and moltenlead is guided in a thin, thread-like stream through the molten aluminumalso in the opening in the bottom of the melting crucible. The meltmixture of for instance aluminum and lead formed in the bottom openingof the melting crucible is then vibrated and mixed by ga jets and blownonto the upper surface of a substrate travelling alongside. A functionallayer produced this way is still nonhomogeneous to a large extent,whereby due to their much greater density the lead particles have astrong tendency to segregate and coagulate as the agitated stream ofmelt mixture is applied onto the surface of the substrate.

A method is known from DE-AS 22 63 268 wherein a melt mixture of leadand aluminum is laterally centrifuged in the form of fine particles by arotor designed as a siphon and segregated on an impact wall where thematerial solidifies in the form of flakes (splatter cooling). However,due to its flake-shaped (leaf-shaped) structure, this material cannot beprocessed to a plating material, by extrusion or by powder rolling.During the production of molded parts using pressure and temperature (bymeans of isostatic presses), segregation occurs again, resulting inextensive nonhomogenity and consequently in unusability of AlPb solidbearings manufactured by this method.

In DE-OS 17 75 322 a slide bearing or a material for its manufacture isdescribed, which consists of Al-alloys (e.g. dispersion alloys based onAlPb or AlSn), wherein the Al material which is later plated on steelserving as a substrate is manufactured by powder rolling. As a result ofthe compaction by powder rolling and of the subsequent rolling andplating operation, the Al bearing material made this way has a bandedarrangement of the soft minority phase (e.g. Pb). Such a bandedstructure is a considerable disadvantage for slide bearings subjected toalternating loads, since permanent cracks are formed in the bands as aresult of the inner notch effect.

PCT WO 87/04377 describes a process by means of which an AlPb strip witha thickness of 1 to 5 mm is produced and then plated onto steel servingas a substrate material. However, the fine lead distribution describedtherein is not achieved in practice, because due to the rolling-platingoperation, the lead is distributed in bands and does not resume theglobular form even during the subsequent heat treatment Besides, it hasbeen found that segregation takes place already in strips which arethicker than 0.5 mm.

This drawback is avoided by DE-PS 37 30 862.9-16 which, while using amelt-spin process similar to the one described in WO 87/04377, has anAlPb foil having a maximum thickness of 0.5 mm and a very fine globulardistribution of lead which is applied on a substrate by ultrasonicwelding, by soldering or gluing thereby avoiding rolling operations.

However, it has been proven that the ultrasonic welding is an expensiveand not particularly reliable procedure, while soldering and gluing arenot suitable for the production by the strip method of semifinishedmaterials to be used in slide bearings.

OBJECTS OF THE INVENTION

It is an object of the invention to provide a process for producing alaminated material for slide elements, having a sliding layer whichapplied onto a support layer and consisting of at least one alloy in theform of a metallurgical two-component or multi-component system with amiscibility gap (monotectic), while a globular fine distribution of thedispersed metal components (the minority phase) in a quasi-amorphousmetallic matrix has to be achieved in the sliding layer.

Still another object is to provide an apparatus for carrying out theprocess according to the invention.

SUMMARY OF THE INVENTION

Such a laminated material is obtained by a process wherein the slidinglayer is continuously cast from the alloy and is subjected immediatelyafter casting to a continuous run through a cooling device with asufficiently high solidification rate to prevent the growth of particlesof the immiscible metallurgical components to a particle size between0.01 and 1 μm, preferably less than 1 μm. Due to the high cooling rate,a uniform globular distribution of the dispersed metal component(minority phase) is frozen in the matrix of the melt. The segregationwhich occurs in alloys of this kind is reduced to a minimum.

Thus, a laminated material is produced whose sliding layer (functionallayer) has considerably improved characteristics due to thequasi-amorphous state of the matrix material and to the substantiallyuniformly globular distribution of the minority phase. The strength ofthe functional layer is thus considerably increased. In spite of theextremely high strength, the ductility and tenacity of the functionallayer are also improved.

Preferably, the alloy or alloys are produced through fusion metallurgyand during their production as well as during their period of readinessfor casting are kept at temperatures above the segregation temperaturecorresponding to the system o composition.

An especially preferred possibility to achieve within the framework ofthe invention a fine globular and most possibly uniform distribution ofthe minority phase in the matrix, consists in the addition of nucleants,corresponding to the relevant alloy type, P, B, Ti, Si, borides,nitrides and/oxides, to the alloy or alloys to be cast in an amountbetween 0.1 and 3.5% by weight. In this way it is possible to cause thevery quick formation of a large number of the finest particles of theminority phase which prevent each other from growing so that even withthe high cooling rate achievable in practice a very fine globulardistribution is obtained in the matrix which solidifies during cooling.In the process according to the invention, systems with a lead minorityphase can be considered, for instance AlPb, FePb, CuPb, MnPb, NiPb andpossibly also CrPb and CoPb. Besides, also similar systems with tin,bismuth or antimony as a minority phase, such as AlSn, AlBi, AlSb, CrSncan be formed. Also PbZn may be used. The invention offers two basicpossibilities:

(a) The dispersion alloy is cast in the form of a thin layer or a filmonto a substrate forming the carrier layer, preferably cast continuouslyonto a strip-shaped substrate. The above-mentioned steps according tothe invention are taken during the casting and the subsequent quickcooling in order to achieve a fine globular distribution of the minorityphase in the metal matrix. The sliding layer can be cast in one or morestages. In the multi-stage casting, initially a first thin film is castand then immediately quickly and efficiently cooled. After thesolidification of the first film, a second film is cast thereon and isalso brought to quick solidification. Such a sliding layer can be builtup in several stages. The individually cast films can be of differentthickness. Also the composition of the alloys of the films can bedifferent. By using different alloys and/or different coolingconditions, it is possible to form within the sliding layer thin layershaving different structures.

(b) Another possibility for the forming of a sliding layer consist infirst casting the sliding layer in the form of a strip or foilindependently of the substrate and then, after cooling, to apply itcontinuously to the substrate by a method of joining, e.g. with the aidof a laser beam.

With the process according to the invention it is possible to producedirectly slide bearings composed of three materials. This can beachieved with the two basic working possibilities by casting the slidinglayer directly onto a travelling strip. If the sliding layer is intendedto be cast independently of the substrate and then attached thereto, aprecoated strip can also be used in this case as a substrate materialfor the sliding-layer foil.

Within the framework of the process according to the invention suchstrips can have a steel backing and an intermediate layer consisting ofthe following alloys:

copper-lead alloys, e.g. Pb 9 to 25%, Sn 1-11%, Fe, Ni, Mn lessthan/equal to 0.7%, the balance being Cu;

copper-aluminum alloys, e.g. Al 5 to 8%, the balance Cu;

aluminum-tin alloys, e.g. Cu 0.5 to 1.5%, Sn 5 to 23%, Ni 0.5 to 1.5%,the balance being Al;

aluminum-nickel alloys, e.g. Ni 1 to 5%, Mn 0.5 to 2%, Cu smallerthan/equal to 1%, the balance being Al;

aluminum-zinc alloys, e.g. Zn 4 to 6%,Si 0.5 to 3%, Cu up to 2%, Mg upto 1%, the balance being Al.

It has been found that a laminated material of steel/intermediate layerwith a functional layer cast thereon or attached by another joiningmethod can be safely and continuously produced this way, preferably withthe desired thickness of the functional layer.

In order to increase the strength of the matrix materials and their wearresistance , other elements may also be added to the melts. It has beenfound that approximately 1 to 4% by weight of silicon, 0.2 to 1% byweight of Mg and 0.1 to 1.5% by weight of Co may be added to an AlPbdispersion alloy to obtain a wear resistant functional layer. In orderto improve the corrosion resistance of the lead minority phase, it isadvisable to further add 0.5 to 3% by weight of tin. To copper-basedalloys, such a CuPb22, usually 0.5 to 2% by weight of Sn and 0.2 to 1%by weight of Fe are added.

In order to improve the bonding strength between the sliding layer andthe intermediate layer, a bonding layer or a diffusion barrier e.g. ofNi, Zn, Fe, Co (particularly with copper-based alloys) and also NiSn,CuZn, CuSn (particularly with aluminum-based alloys) is provided betweenthe sliding layer and the intermediate layer.

In order to carry out the process, it is preferred to star out with adevice provided with a crucible for melting and/or holding in readinessan alloy in the form of a metallic two-component or multi-componentsystem with a miscibility gap, with casting means connected to thecrucible and serving for casting a strip from the alloy, and furtherwith means for receiving the cast strip and for its removal from thecasting point, as well as with cooling means for the cast alloy stripleaving the casting point. According to the invention, the castingarrangement has to be built for the formation of a film-shaped orfoil-shaped thin strip, either independently of or cast onto a substrateand the cooling means have to be provided with a forced-cooled receivingsurface for the cast foil or forced-cooled support surface for thesubstrate to receive the cast material and also with highly effectivecooling units directed onto the free surface of the cast foil or castfilm.

In particularly advantageous embodiments, the device is equipped withstrongly forced-cooled rollers, particularly a strongly forced-cooledroller for taking up the cast foil or carrier for the substratereceiving the casting In another embodiment of a device according to theinvention a flat, optionally cooled, guide or transport path may beprovided. Transversely to this guide or transport path, a casting flowdevice for the melted alloy is arranged, located at an adjustabledistance above the guide path or a substrate positioned on the guidepath. Such casting flow devices facilitate in a particularlyadvantageous manner the casting onto a substrate of a sliding layerbuilt up in several stages. For this purpose, several spaced-apartcasting flow devices are arranged in the direction of travel and betweenthese casting flow devices and behind the last one of these devicescooling units are arranged, which act on the free surface of the castfilm or on the free surface of the cast foil.

BRIEF DESCRIPTION OF THE DRAWING

The above and other objects, features and advantages will become morereadily apparent from the following description, reference being made tothe accompanying drawing in which:

FIG. 1 is a considerably enlarged partial section of a laminatedmaterial comprising a cast-on sliding layer of a dispersion alloy;

FIG. 2 is a considerably enlarged partial section of a laminatedmaterial according to another embodiment;

FIG. 3 is a diagrammatic representation of a first embodiment of aproduction device;

FIG. 4 is a diagrammatic representation of a production device modifiedwith respect to FIG. 3;

FIG. 5 is a diagrammatic representation of yet another embodiment of thedevice according to the invention;

FIG. 6 is a diagrammatic representation of an embodiment of the devicesaccording to the invention;

FIG. 7 is a diagrammatic representation of a further embodiment of thedevice, according to the invention;

FIG. 8 is a considerably enlarged partial section of a laminatedmaterial produced in a device according to FIG. 7 with a soldered-onsliding layer of a dispersion alloy.

SPECIFIC DESCRIPTION

FIG. 1 shows a very enlarged partial section of a laminated material 10with a cast-on sliding layer 13 of a dispersion alloy AlPb8Si4SnCu andan intermediate layer 12 of AlZn5SiCuPbMg with a steel backing 11 Thesliding layer (functional layer) 13 consists of a quasi-amorphousaluminum matrix containing finely distributed globular lead particles,of which only the largest lead particles 14 are visible in theillustration of FIG. 1, their size being of the order of 10⁻² μm. Alarge number of lead particles are smaller and not visible in theenlargement scale selected for FIG. 1. Among others, the large number oflead particles is generated by the addition to the dispersion alloy of anucleant adjusted to the alloy type, for instance P, B, Ti, or Si,boride, nitride or oxide, in a proportion by weight of approximately 2%. In this way, a very large number of very fine lead particles wasproduced in the dispersion alloy, which during the casting and coolingof the sliding layer 13 have prevented each other from growing. Throughquick cooling or chilling with a cooling rate of the order of 10² to 10⁶K/s, a large number of lead particles could be kept so small that theirsize remained below 10⁻² μm. The segregation of the lead particles couldbe strongly reduced both in the case of large lead particles 14, as wellas invisible small lead particles through very quick cooling or chillingof the sliding layer 13. The crystallization of the aluminum, which istypical for aluminum, was reduced in the aluminum matrix of the slidinglayer 13 by the influence of crystallization inhibitor (glass formers)for which, for instance Si, B, P, Fe, Co or Ti can be used eitherindividually or in mixtures in a proportion of 0.2 to 2% by weight andby a very quick cooling of the cast-on sliding layer 13.

In contrast to the sliding layer 13, the intermediate layer 12 shows astructure which is typical for cast-on aluminum alloys.

The example shown in FIG. 2 is a laminated material 10 with a supportlayer 11 made of steel and a sliding layer 13 as a functional layerconsisting of an aluminum/lead dispersion alloy AlPb10Si7SnCu, i.e. witha lead content of 10% by weight and a content of silicon of 7% by weightwhich in this case acts both as a nucleant for the minority phase leadand also as a crystallization inhibitor in aluminum. As can be seen fromFIG. 2, in the quasi-amorphous aluminum matrix of the functional layer13 there are dispersed lead particles 14 in a fine globulardistribution, while again only the larger lead particles with a size ofabout 10⁻² μm are visible. The silicon is mostly dissolved in thequasi-amorphous aluminum matrix as a glass former and in a smaller partintegrated into the minority phase lead as a nucleant Tin is integratedinto the lead essentially for protection against corrosion.

The intermediate layer 16 consists in this example of a dispersion alloyCuPb22Sn and present a distribution of the lead particles 17 which istypical for this dispersion alloy.

One embodiment of a device for carrying out the method for theproduction of the-described laminated material having a sliding layer 13made of alloys with a miscibility gap is shown in FIGS. 3 and 4 in twovariants

The alloy or dispersion alloy is melted and introduced in a crucible 21having at its lower end an outlet 22 for a fine jet 23 of the melt. Asindicated by arrow 24, from above gas under pressure is forced into thecrucible 21, this gas being inert towards the melt and dissolving aslittle as possible in the melt. In the illustrated examples, thecrucible 21 is surrounded by an induction coil 25, which keeps the meltat a preselected temperature and sufficiently liquid to be pressedthrough the outlet 22 and form a thin jet 23 For the processing of adispersion alloy, the crucible can be additionally provided withagitator or vibrators which permanently and intensively mix the meltmixture of the dispersion alloy and keep the components of the mixturein a fine distribution. For the sake of simplicity, these mixers orvibrators were not shown in FIGS. 3 and 4.

The support layer 11 is unwound from a reel in the form of a metal stripand guided onto a strongly forced-cooled cylinder 26. Before the metalstrip 40 reaches the cylinder 26, it passes through a device 41 for thecleaning and deoxidation of its surface, for instance a brushing device,to insure that the surface of metal strip 40 to be coated is free ofoxides. For further preparation for the casting, the metal strip 40passes through a tempering device 43 to insure the immediate bonding ofthe cast-on alloy with the surface of the metal strip 40. In order tomaintain the established state up to the moment of casting, the metalstrip 40 is guided up to the outlet of crucible 21 in an atmosphere ofprotective gas, as indicated by the protective hood 42. In theillustrated example, the casting itself, as well as subsequent coolingtake place under this protective hood 42

The thin, strip-shaped or planar jet 23 of molten alloy or moltenmixture of a dispersion alloy pressed downwards from the crucible 21 bypressure regulating means 100 meets in the embodiment shown in FIG. 3the surface of the metal strip 40 at an acute angle δ. The angle δ isselected so that the jet 23 is immediately distributed over the surfaceof metal strip 40 in the form of a thin film without splashing. Thecooling is provided primarily by the cylinder 26. But in order tointensively cool also the exposed coated surface of the laminatedmaterial 10, in the embodiment of FIG. 3 jets 28 of cool gas or coolliquid are provided which are directed onto the layer 20. The laminatedmaterial 10 is separated from cylinder 26 by strip remover 29.

The cooling rate of layer 20 on the cooled cylinder 26 under theopposite action of cooling jets 28 ranges from above 10² K/s up to about10⁶ K/s. Correspondingly a true alloy which forms the film 20 is kept inquasi-amorphous state, particularly when crystallization inhibitors(glass formers), have been added to the alloy. If a dispersion alloywith a miscibility gap of its components is processed, a film results inwhich the component of the dispersion alloy forming the matrix is in aquasi-amorphous state, while the component dispersed in the matrix(minority phase) is globular and finely distributed in the matrix.

In a modus operandi according to FIG. 4 the melt mixture of a dispersionalloy is put into a crucible 21 where it is set under pressure by agaseous medium as shown by arrow 24. From the outlet 22 at the lower endof crucible 21 flows the melt or melt mixture in a jet 23 into a gap 30between the metal strip guided over roller 31 and an opposite roller 32.Both rollers 31 and 32 are strongly forced-cooled. The width of gap 30between the rollers is adjusted according to the desired thickness ofthe layer 20 to be produced. As indicated in FIG. 4, a slightaccumulation of melt or melt mixture is formed upstream of gap 30without causing any delay worth mentioning at the point of transfer ofthe melt or melt mixture from outlet 22 of crucible 21 into the gap 30.Therefore, the two rollers 31 and 32 do not exert any pressure worthmentioning onto the laminated material being produced, but have only acertain smoothing effect on the surface of the created layer 20.Further, this small accumulation of material at the gap results in adistribution of the melt or melt mixture in the axial direction ofrollers 31 and 32, so that even strips can be produced, whose width isgreater than the one which can be produced according to the example ofFIG. 3. In order to facilitate this axial distribution of the melt orthe melt mixture along the gap 30, the crucible 21 is inclined at anangle θ so that the melt or melt mixture under pressure in crucible 21may be injected directly into gap 30.

The surface of roller 32 is so made that practically no bonding with themelted alloy or one of the components of a dispersion alloy to beprocessed occurs. In order to fasten the film 20 formed in gap 30 on thesurface of the metal strip 40, the upper roller 32 is provided with astrip remover 33. In order to cool the free surface of film 20 formed atthe outlet of gap 30, a cooling nozzle 34 is provided which directs ajet of cold gaseous or liquid medium towards the outlet of gap 30.

The metal strip 40 is further cooled by the cooling roller 31 in orderto produce additional cooling, respectively to avoid a reheating of thefilm 20 by the metal strip 40.

Opposite to the cooling roller 31, a third cooling roller 35 is located,which is strongly forced-cooled to further cool the film 20 at itssurface chilled by roller 32 and the coolant jet sprayed by nozzle 34.Downstream of the third cooling roller, a fourth cooling roller 36 isprovided which takes u from roller 31 the metal strip with the film 20.In order to force an effective application of the film 20 onto thesurface of the fourth cooling roller 36, a deflection roller 38, whichis also cooled, is provided oppositely to the fourth cooling roller 36.The strip of laminated material 10 is removed from the fourth coolingroller 36 by a strip remover 39. As can be seen from FIG. 4, a secondcooling nozzle 34' is arranged between the cooling rollers 35 and 36 anda third cooling nozzle 34" is arranged between the rollers 31 and 38. Incomparison to the method according to FIG. 3, a further intensificationof the cooling process takes place in the embodiment according to FIG.4, so that the film 20 which becomes the sliding layer 13 is subjectedto cooling rates ranging between 10³ K/s to 10⁶ K/s. Thereby thepossibility arises to produce layers 20 of greater thickness, forinstance 0.5 mm, which may be so intensively chilled over their entirethickness that the amorphous state of the metallic material is frozenduring cooling. The method according to FIG. 4 finally makes possiblethe production of wider strips, particularly when several crucibles 21are arranged next to each other along ga 30.

If a strip of laminated material 10 with an intermediate layer 12 or 16is to be produced, a metal strip 40 in the form of a laminate is fed tothe device according to FIG. 3 or FIG. 4, which has already beenprovided with the metal of the intermediate layer on the side to becoated.

In the examples illustrated in FIGS. 5 and 6, the metal strip 40representing the cast-on substrate, moves continuously at a speed v inthe direction of travel 44 indicated by an arrow, on a guide andtransport path 45, which can be forced-cooled. A casting flow device 46belonging to a casting device is locate at a distance above the guideand transport path 45. The distance of the casting flow device 46 fromthe guide and transport path 45 is adjusted so that between the lowersurface of the casting flow device 46, which extends substantiallyparallel to the guide and transport path 45, and the upper surface ofmetal strip 40, which is located on the guide and transport path 45, itcorresponds to a preselected distance d which is such that the alloymelt is basically prevented from flowing out due to its surface tensionin the gap formed as can be seen in the left-hand part of FIG. 5. On theside where the metal strip 40 moves away from the casting flow device46, a film 20 is formed by adhesion of the alloy melt to the surface ofthe metal strip 40. The thickness δ of the film 20 is smaller than thedistance d of the lower surface of the casting flow device 46 from thesurface of the metal strip 40, but can be reproduced and calculated onthe basis of the distance d, the travel speed v of metal strip 40, thepressure exerted on the melt and the flow volume rate V of the meltinfluenced thereby, and also by the dimensions 1₁ and 1² of the castingflow device 46.

The film formed on the metal strip 40 when leaving the casting flowdevice 46 is very quickly cooled on the one hand by the cooled metalstrip 40 and on the other hand by a cooling unit possibly directed ontothe free surface of the film 20, for instance gas jets or liquid jets,with a cooling rate of for instance 10² to 10⁴ K/s.

As shown in FIG. 6, a casting device provided with a casting flow device46 is particularly suitable for a multi-stage buildup of the slidinglayer of two or more films (here 20a and 20b) cast successively onto thesubstrate. The two-stage or multi-stage buildup of the sliding layer hasthe advantage that the very thin alloy film 20 can be correspondinglyquickly cooled, so that cooling rates of the order of 10³ to 10⁵ K/s canbe easily achieved. Between the successive casting flow devices andafter the last one of these casting flow devices 46, cooling units canbe provided, which are directed onto the free surface of the respectivejust freshly formed alloy film 20, these cooling units consisting of forinstance nozzle arrangements 27 producing coolant jets 28. In theexamples shown in FIGS. 5 and 6, the casting flow device 46 extendsacross the guide and transport path 45, generally at right angles to thedirection of travel 44. However, it is also conceivable to incline thecasting flow device inclined at an angle above the guide and transportpath 45

In the example of FIG. 6 it is provided that the films 20, formed forthe coating of the substrate or metal strip 40 are made of the samealloy and have the same thickness δ₁ and δ₂. Of course, a certaindifference can be expected in the structure of the partial layers of thesliding layer formed by the films 20a, 20b, because the lower partiallayer is at least partially reheated during the casting of the secondfilm 20b.

Generally, the device in its embodiment according to FIGS. 5 and 6offers particularly advantageous control possibilities. For instance,the defined thickness of the liquid film can be adjusted by adjustingthe advancement speed by adjusting means 101 shown in FIGS. 1 and 6 ofthe solid metallic substrate. Also the cooling rate of the cast-on layermay be adjusted by any convention control means 102 receiving substratespeed, the distance between the outlet of the crucible and the substrateand injection speed of the alloy data from the adjusting means 101receiving in turn pertinent data from speed control means 103 andpressure regulating means 100. The adjustment of the defined thicknessof the liquid film can also be achieved by changing the geometry of theoutlet for the alloy, namely by changing the distance d between thelower side of the casting flow device 46 and the surface of metal strip40 and also by changing the dimensions of the casting flow device 46. Byadjusting the distance d between the lower side of the casting flowdevice 46 and the surface of metal strip 40 it is also possible toinfluence and adjust the cooling rate of the cast-on layer, by controlmeans 102 connected with nozzles respectively the cast-on film 20.

In FIG. 7 an embodiment is illustrated wherein first a foil 47 formingthe sliding layer is produced independently of the substrate or metalstrip 40 and after cooling and solidification is joined by means oflaser beams with the metal strip 40. In this device the alloy ordispersion alloy are introduced in molten state in the crucible 21 whichat its lower end has an outlet 22 for the melt jet 23. The melt jet 23arrives directly on the surface of a strongly forced-cooled cylinder 26and forms there a foil 47 which is rapidly cooled by the cylinder 26 andpassed underneath a nozzle arrangement 27 from which jets 28 of cold gasor cold liquid are directed onto the free surface of foil 47. Thethickness of the foil 47 can be determined by the rotational speed ofthe cylinder 26 and by the expelling pressure built up inside thecrucible 21 by an inert gas, as indicated by arrow 24. The casting ofthe dispersion alloy or alloy onto the surface of the cylinder 26 takesplace at an angle δ which is selected so that no parts of the meltsplash when coming in contact with the surface of cylinder 26. Thesurface of cylinder 26 is built so that bond is formed between thecast-on alloy and the cylinder surface, but only intensive heat transferoccurs.

The cooling rate of foil 47 on the forced-cooled cylinder 26 and theopposite action of the cooling jets 28 lies between approximately 10⁶and approximately 10⁸ K/s up to approximately 10⁹ K/s Consequently, atrue alloy forming the foil 47 is basically kept in an amorphous state.If a dispersion alloy whose components have a miscibility gap isprocessed in this manner to form a foil 47, a matrix in a basicallyamorphous state is produced in this foil 47, while the componentdispersed in this matrix is globular and exceptionally finelydistributed. The foil produced in this manner is transferred to astrongly forced-cooled roller 32. The foil 47 is separated from theroller 32 by a strip remover 33. Opposite to the roller 32 a stronglyforced-cooled roller 31 is located so that a gap 30 is formed, intowhich the foil 47 and a strip-like substrate, e.g. a metal strip 40,wound around roller 31 are directed. A bundle of laser beams 48 isdirected into this gap at an angle α in such a way that the joiningsurfaces of foil 47 and of metal strip 40 are slightly heated. Bypressing them lightly together, without any significant reduction oftheir thickness, the foil 47 and the metal strip 40 are solderedtogether along the heated surfaces. The strips joined this way arefurther cooled between the roller 31 and oppositely arranged coolingroller 35 and are transferred to a fourth cooling roller 36. Opposite tothis fourth cooling roller 36, a deflection roller 38 which is alsocooled is arranged. The strip 10 of laminated material is then taken upfrom the fourth cooling roller 36 by a strip remover 39. In contrast tothe method according to FIGS. 3 and 4 and also to the method of FIGS. 5and 6, a certain warming of the surfaces to be soldered together isnecessary. As a consequence, some structural changes must be expected inthe soldered surface areas as can be seen from FIG. 8. FIG. 8 shows astructure of the laminated material 10 which corresponds substantiallyto that shown in FIG. 1, the laminated material being composed of abacking material 10 made of steel, an intermediate layer 12 ofAlZn5SiCuPbMg and a sliding layer 13 of a dispersion alloy AlPb8Si4SnCu.In contrast to the laminated material according to FIG. 1, the laminatedmaterial in FIG. 8 shows some coarsening in the structure of theintermediate layer 12 on the junction surface 49 facing the slidinglayer 13. In the sliding layer 13, in the area of the soldered-onjunction surface 49 facing the intermediate layer 12, somewhat largerlead particles 14 were formed as a result of the heating required forsoldering. This structure coarsening and the formation of somewhatlarger lead particles 14 are quite acceptable in view of the fact thatby producing the sliding layer 13 as a foil a much quicker cooling ofthe foil forming the sliding layer 13 becomes possible, so that in thesliding layer 13 the aluminum matrix itself presents much strongeramorphous properties than in the example of FIG. 1, a difference whichis however not visible at the enlargement scale selected for FIG. 8.

We claim:
 1. A process for making a laminated material for a slideelement, said process comprising the steps of:(a) forming a substrateincluding at least one backing layer; (b) continuously transporting thesubstrate along a path of the substrate; (c) making at least one alloyincluding at least two metallurgical components with a monotecticmisability gap of immiscible particles; (d) continuously casting afunctional layer at a predetermined rate from the alloy on the backinglayer, at least at one location along the path, thereby forming thelaminated material; and (e) thereafter solidifying the functional layerat a high cooling and solidification rate while continuing to advancethe material along the path to prevent the growth of immiscibleparticles in the functional layer above 1 μm and to form said particlesin a dimension range between 0.01 and 1 μm.
 2. The process defined inclaim 1 wherein the particles are less than 1 μm in size.
 3. The processdefined in claim 1 wherein the step (c) includes the steps of:fusing thecomponents, and maintaining a temperature of the alloy above asegregation temperature corresponding to its composition.
 4. The processdefined in claim 3 wherein the step of maintaining the temperaturefurther including a step of controlling the temperature of the substratewith respect to the cooling parameters corresponding to adhesion of thefunctional layer to the substrate.
 5. The process defined in claim 1wherein a nucleating agent selected from the group of P, B, Ti and Siboride, nitride and oxide is added to said alloy.
 6. The process definedin claim 1 wherein in step (c) the components are added sequentially. 7.The process defined in claim 1 wherein in step (c) the components areadded simultaneously in a proportion between 0.1 to 3.5% of weight. 8.The process defined in claim 1 wherein in step (e) further includescontrolling the cooling rate in response to a casting rate.
 9. Theprocess defined in claim 1 wherein in step (d) further includescontrolling a casting rate by varying a dosage of the alloy, therebyselecting a desired thickness of the functional layer at the applicationlocation.
 10. The process defined in claim 1 wherein in step (d) furtherincludes controlling a speed at which the substrate is transported fromthe application location, thereby selecting a desired thickness of thefunctional layer at the application location.
 11. The process defined inclaim 8 wherein in step (e) further includes controlling the coolingrate in response to a speed at which said substrate is transported. 12.The process defined in claim 1 wherein the alloy is AlPb, FePb, CuPb,MnPb or NiPb, including a respective content of the lead higher than arespective eutectic composition determined by the alloy, the content ofthe lead being up to 4% by mass in each of the alloys.
 13. The processdefined in claim 8 wherein in step (d) further includes a step ofjoining the substrate and the functional layer by a laser beam, thefunctional layer being a strip upon applying on the substrate.
 14. Theprocess defined in claim 8 wherein in step (c) further includes thesteps of:accumulating the alloy in a crucible, the crucible being formedwith an outlet, and changing a geometry of the outlet of the crucible,thereby controlling the extrusion rate and obtaining the desiredthickness of the functional layer.
 15. The process defined in claim 13wherein the step (d) further includes a step of varying a distancebetween the substrate and the outlet of the crucible, thereby obtainingthe desired thickness of the functional layer.
 16. The process definedin claim 1 wherein said step (d) is performed at two applicationlocations along the path of the substrate, said substrate being ametallic strip delivered to the locations and receiving a respectivefunctional layer applied as a liquid film from a respective alloy ateach of the application locations.
 17. The process defined in claim 10further including the steps of:(a) controlling the extrusion rate ateach of the location, the extrusion rate at one of the locations beingdifferent from the extrusion rate at another location, and (b) adjustingthe cooling rate at each of the locations in response to a respectivecasting rate, thereby forming the laminated material including aplurality of separate functional layers joined together and havingrespective different thickness.
 18. The process defined in claim 16further including a step of modifying a composition of the respectivealloy at each of the locations.
 19. The process defined in claim 16wherein said substrate and said functional layer are cooled along thepath of the material between the application locations.
 20. The processdefined in claim 1 further comprising the step of pressing thefunctional layer against the substrate upon cooling of the functionallayer at a pressing location downstream of the application location. 21.The process defined in claim 1 further comprising a step of applying anintermediate layer on the substrate upstream from the applicationlocation, the intermediate layer being composed of another alloyselected from the group consisting of:a copper-lead alloy including from9 to 25% of Pb, up to 11%, of Sn, and Fe, Ni, at most 0.7% of Mn and thebalance copper; a copper-aluminum alloy including from 5 to 8% of Al andthe balance copper; an aluminum-tin alloy containing from 0.5 to 1.5% ofCu, from 5 to 23% of Sn, from 0.5 to 1.5% of Ni, and the balance Al; analuminum-nickel alloy including from 1 to 5% of Ni, from 0.5 to 2% ofMn, at most 1% of Cu an the balance aluminum; and aluminum-zinc alloyincluding from 4 to 6% of zn, from 0.5 to 3% of Si, at most 2% of Cu, atmost 1% of Mg and the balanced Al.
 22. An apparatus for carrying out aprocess for manufacturing of a laminated material for slide elements,said apparatus comprising:delivering means for continuously transportinga substrate including at least one backing layer along a path of thesubstrate; at least one crucible along the path for making an alloyincluding at least two metallurgical components having a plurality ofimmiscible particles; casting means operatively connected with thecrucible for casting from the alloy a strip of a functional layer on thesubstrate at a casting rate at at least one application location, saidstrip and said substrate forming a laminated material; applying meansdownstream from the crucible for removing the strip of functional layerapplied on one side of the laminated material from the applicationlocation; separating means downstream from the applying means forremoving the strip of functional layer from the applying means; andcooling means along said path for cooling the laminated material at acooling rate, said cooling means including: at least one guide formedwith a receiving forced-cooled surface taking up said laminated materialat said application location and juxtaposed with another side of thelaminated material opposite the one side, sprinkling means spacedlyjuxtaposed with the laminated material for sprinkling a coolant thereon,and a plurality of cooling rollers along said path downstream from theguide, the functional layer being solidified at a cooling rate with theimmiscible particles in the being in a dimension range between 0.01 and1 μm.
 23. The apparatus defined in claim 22 further comprising controlmeans for adjusting the cooling rate in response to the casting rate.24. The apparatus defined in claim 22 further comprising adjusting meansfor controlling the casting rate of said strip from the crucible. 25.The apparatus defined in claim 24 wherein the crucible is formed anoutlet spaced at a distance from the substrate, said adjusting meansadjusting a distance between the outlet and the substrate, so that athickness of said strip is adjustable.
 26. The apparatus defined inclaim 23 wherein said casting means includes pressure varying means forvarying a speed at which said strip is ejected from the crucible. 27.The apparatus defined in claim 24 wherein said adjusting means includesspeed control means for controlling a speed at which said substrate isadvanced along path.
 28. The apparatus defined in claim 23 wherein saidguide is another roller.
 29. The apparatus defined in claim 28 whereinsaid other roller rotates at a controlably varying speed.
 30. Theapparatus defined in claim 22 wherein said sprinkling means includes aplurality of nozzles, at least one of said nozzles being directed atsaid functional layer of said laminated material at said applicationlocation.
 31. The apparatus defined in claim 30 wherein said pluralityof nozzles being adapted to cool said one and opposite sides of thelaminated material along said path.
 32. The apparatus defined in claim23 wherein said plurality of cooling rollers being adapted to contactsaid one and opposite sides of the laminated material along said path.33. The apparatus defined in claim 23 wherein said application meansincludes a drum, said drum being juxtaposed with said functional layerand defining said application location with said guide juxtaposed withthe opposite side of the substrate.
 34. The apparatus defined in claim22 further comprising two crucibles for making alloys, each of saidcrucibles extracting a respective strip of the functional layer at arespective application location at a respective controllable castingrate.